Effect of infiltrated polyamines on polygalacturonase activity and chilling injury responses in zucchini squash ( Cucurbita pepo L.)

• Published in: Biochemical and biophysical research communications 2002-07, Vol.295 (1), p.98-101
• Main Authors: Martı́nez-Téllez, M.A, Ramos-Clamont, M.G, Gardea, A.A, Vargas-Arispuro, I
• Format: Article
• Language: English
• Subjects: Chilling-injury; Cold Temperature; Cucurbita - drug effects; Cucurbita - enzymology; Cytoprotection; Dose-Response Relationship, Drug; Firmness; Ion Transport - drug effects; Polyamines; Polyamines - pharmacology; Polygalacturonase - metabolism; Polygalacturonase-activity; Putrescine - pharmacology; Spermidine - pharmacology; Spermine - pharmacology
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)00631-9

The effect of exogenous polyamines on electrolyte leakage, chilling index, polygalacturonase activity (PG), ethylene production, and firmness in zucchini squash fruits stored for 12 days at 2 °C or 10 °C, 85–90% RH was evaluated. Fruits were infiltrated with putrescine (PUT) spermidine (SPD) and spermine (SPM) at 0.1, 0.25, 0.5, 2.0, and 4.0 mM. All polyamines exerted a protective effect on cell and organelle membranes. The most effective was SPD, which reduced electrolyte leakage between 62% and 82%, compared to control fruits stored at 2 °C. At 10 °C they did not exhibit chilling injury (CI) symptoms, while at 2 °C SPM (0.5 mM) and SPD (0.5 mM) diminished them 92% and 100%, respectively; which extended storage life for 8–10 days at 2 °C. High concentrations of polyamines ( >2.0 mM ) caused the appearance of CI symptoms. PG activity diminished proportionally to the concentration of polyamine except for the concentration at 4.0 mM. No significant changes were observed in ethylene production.